1Field of the Invention
A total luminous flux measurement system and a total luminous flux measuring method is provided according to the present invention; more particularly, field patterns of a light emitting component are calibrated and calculated so that the accuracy of inspecting the total luminous flux is enhanced.
2Description of the Prior Art
LEDs have many advantages such as lower energy consumption, longer lifetime, faster reaction speed, etc.; therefore, LEDs have enormous potential and are highly praised. In the industrial chain of LEDs, epitaxial wafers are manufactured and then integrated as LED wafers; LED wafers are cut into LED chip dies, which are then packaged in various forms. The luminous efficiency of LEDs has been, a target that manufacturers go for. Thus, the luminous flux of LEDs is inspected all the time during the whole process of manufacturing so as to confirm whether the luminous efficiency of LEDs meets the expectation.
According to present total luminous flux measurement system, integrating spheres and solar panels are utilized for covering the emitting direction of LEDs so as to calculate the total luminous flux by converting the current value measured. Although the method is convenient, it is problematic. For example, the size of the openings of integrating spheres is limited and if the openings are too big, the current to be measured is too small and thus the accuracy is low. In order to cover as much luminous emitted from LEDs as possible, integrating spheres are put very close to LEDs—LED chip dies are sent inside the integrating spheres via jigs for measuring. As a result, although an measurement system utilizing integrating spheres has greater accuracy, it takes more time and does not suitable for quickly measuring uncut LED chip dies on LED wafers.
A measurement system utilizing solar panels utilizes photovoltaic cells as a light receiving component. Photovoltaic cells have advantages such as larger light receiving area, single crystal silicon being more stable, better repeatability of output current, shorter response time, etc. and thus effectively reduces errors occurred due to light receiving percentage brought by structural differences in microscope point measuring system. However, although in the measurement system utilizing solar panels, light receiving amount can be increased by enlarging the size of solar panels, its efficiency greatly depends on the incident angles so that the measuring result has many errors.
Refer to FIG. 1, which is a diagram showing a relation between incident angles and absorption efficiency when a beam is directed to a solar panel in prior art. The incident angles in FIG. 1 represent an angle between the beam and a normal of a solar panel. When the incident angle is 0 degree, the beam is incident on the solar panel vertically and thus the absorption efficiency is the highest. However, the larger the incident angle is, the lower the absorption efficiency becomes because the beam reflects more easily when the incident angle is larger; as a result, the absorption efficiency becomes lower. In conclusion, when solar panels are utilized as light receiving components for inspecting the total luminous flux of LEDs, errors tend to occur, and errors differ among various field patters of projection fields of LEDs.
Thus, a total luminous flux measurement system for measuring a total luminous flux of a light emitting component is provided according to the present invention so as to improve the accuracy of inspecting the total luminous flux of a light emitting component.